He walked in the training room. Tony and Nat were there. He approached her while she was resting a bit. Tony stepped aside to give them a little privacy.
Steve: "Hey darling"
Nat: "Hey love"
Steve: "I have planned a little surprise for you love."
Nat: "What is it honey, please tell me a bit more"
Steve: "Just be ready by 7 tonight ok ?"
Nat: "That's all you're gonna tell me ?"
Steve: "Yes. And please honey, beat the shit out of Stark"
Nat: "How can you even think that I wouldn't."
Tony: "I heard that !"
They both laughed. Steve kissed her before stepping out of the training room. Nat and Tony kept training for a while more.